1. Field of the Invention
The invention relates to controls for fluid-operated motors used to the unlocking and locking of parts such as dump trailer tailgates. It is important to prevent inadvertent unlocking of such parts due to temporary reduction or loss of pressure, followed by reapplication of full pressure.
2. Description of the Prior Art
It is known to have safety valve means for systems of this type which operate on the principle of manual movement to one position, the valve means being spring-urged to a safety position with piston means holding the valve means against the spring so that low pressure is monitored for safety purposes. However, such prior art constructions have several drawbacks in terms of lack of simplicity and in ability to control double acting fluid motors.